@chrbayer Great! If I were you, I'd base it on the vanilla v8. Have a look at the PKGBUILD for this package (jre7-openjdk-headless-infinality et al.) and compare it to the vanilla jre7-openjdk. You should be able to make similar modifications to your package. Apart from that, the build process is pretty straightforward.

@chrbayer I'd definitely be keen. I imagine that most v7 users would be keen to at least test v8, even if they eventually move back. How complicated is it? An AUR package is definitely preferred in terms of ease of installation.